Connexion

- Fix error codes for bad Content-Types in body validator. (629)
- Add validator kind to error logs extra in validators (671)
- Improve metrics reporting (672)
- Improve coroutine detection (600)
- Add x-nullable support for body validators (642)

Bugfix:
- Split FormData array parameters correctly (638)

- Fix log line to wrong logger

- Update to swagger-spec-validator 2.3.1 (611)
- URI parsing decorator (613)
- Correct validator response on bad JSON (610)
- Add capability to pass framework's request context to handler functions

This release contains no Python code changes!

* 584: fix [PyPI description](https://pypi.org/project/connexion/#description) rendering

* 583: make Connexion compatible with the latest gevent version